It used to be a lot easier to be physically active then it is today, and we'll discuss this later in the class, but energy saving devices all over the place.

在过去,人们比现在从事更多的体力活动,这一点我们以后再讲,帮助你省力的装置,如今随处可见

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选